Valve bag



March 26, 1957 R. A. PORT VALVE BAG 2 Sheets-Sheet 1 Filed June 2, 195.4

Richard A Port INVENTOR. By WM.

am flowfim March 26, 1957 PORT 2,786,623

VALVE BAG Filed June 2, 1954 2 Sheets-Sheet 2 R/b/I am A. Por/ INVENTOR.

aitsd Sees Patent VALVE BAG Richard A. Port, Monroe, La., assignor, by mesne assignments, to Olin Mathieson Chemical Corporation, a corporation of Virginia Application June 2, 1954, Serial No. 433,932

2 Claims. (Cl. 229-625) This invention relates to a valve bag and more specifically provides an improved construction in multiple ply type valve bags. An object of this invention is to provide an improved valve bag structure of the multiple ply type wherein a top corner is folded inwardly for forming a valve corner and one of the plies extends beyond the severance edge of the remaining plies thereby forming a valve flap for efiectively sealing the opening of the bag to prevent sifting or leakage of contents through the valve.

A further object of this invention is to provide a multiple ply valve bag having an intermediate ply with a cut-out portion on the opposite end of the bag from the valve corner equal in area to the projection forming the valve flap thereby weakening the valve bag and the specific construction of this invention includes a reinforcing sheet for replacing the weakened area.

Still another object of this invention is to provide a valve paper bag which is simple in construction, strong, unaffected by the cut-out area forming the valve flap, well adapted for its purposes and relatively cheap to manufacture.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure 1 is a group perspective showing the three plies of the multiple ply bag of the present invention with the reinforcing sheet;

Figure 2 is a perspective view showing the valve bag of the present invention in assembled relation;

Figure 3 is a top plan section taken substantially along section line 3-3 of Figure 2 showing the arrangement of the cut out area and the reinforcing sheet;

Figure 4 is a perspective view showing the valve end of the paper bag in condition for sealing; and

Figure 5 is a perspective view showing the construction of Figure 4 in an extended position.

Referring now specifically to the drawings, it will be seen that the numeral generally designates the paper bag of the present invention formed from an outer ply 12, an inner ply 14, and an intermediate ply 16. The outer ply 12 and the inner ply 14 are each equal in length and include a projecting valve corner 13 at one end thereof and a smooth severance edge at the other end. The intermediate ply 16 is provided with a valve flap extension 20 and a corresponding cut-out portion 22 at the other end thereof which provides a valve flap 20 on the next succeeding ply which is cut from a continuous cylinder. When the outer ply 12, the inner ply 14 and the intermediate ply 16 are assembled, the cut-out portion 22 forms a weakened area which gives an effective thickness of only two plies. In order to correct this weakened condition, a reinforcing sheet 24 having a valve corner extension 26 and being the same length as the inner ply 12 and the outer ply 14 is positioned between 2,786,623 Patented Mar. 26, 1957 ice the inner ply 14 and the. intermediate ply 16' thereby reinforcing the cut-out area 22 and giving, a three ply thickness throughout the entire area of the valve bag 10. Each of the plies of the valve bag 10 is provided with a gusseted side portion 28 and it will be seen. that the reinforcing sheet 24 bridges the side or gusseted area 28 and also extends fractionally across the face width of the valve bag 10. Further, it will be seen that the extension 20 on the intermediate ply 16 forming the valve flap is provided with a slit 30 to facilitate the en trance of the filling spout.

The operation of the device will be readily understood. The plies 12, 14 and 16 are cut from continuous tubular members in an obvious manner and the area forming the extension 20 on the intermediate ply forms a cut-out in the adjacent intermediate ply thereby weakening the valve bag. The reinforcing sheet is formed along with the other plies of the multi-walled tube between the plies with its side edges located equal distance from the side edges of the bag length and extending fractionally of the bag face width. Obviously, the width of the reinforcing sheet may be determined by experimentation to correct the weakened condition caused by the cut-out area in the intermediate ply. The valve extension 20 may be slit to allow material readily to be discharged from the filling spout as desired. Further, the bag may be closed in any suitable manner such as stitching over crepe tape and it will be understood that the material in the bag will force the valve extension 20 into intimate contact thereby sealing the valve in an obvious manner.

From the foregoing, the construction and operation of the device will be readily understood and further explanation is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the appended claims.

What is claimed as new is as follows:

1. A valve bag comprising a body portion formed of at least three flattened tubes gusseted at their sides and including an inner tube partially surrounded by a reinforcing sheet and surrounded by an intermediate tube and an outer tube, said intermediate tube having an extension on the top gusseted corner portion, said extension projecting beyond the outer and inner tubes and terminating in an edge parallel to the outer edges of the inner and outer tubes, said extension being folded inwardly of the bag to form a valve flap adapted to be pressed up against the inside top portion of the bag when filled to prevent sifting of contents through the valve, said intermediate tube having a cut-out space equal to the valve flap extension space in the other end of said tube, said cut-out area being covered by the inner and outer tubes and by the reinforcing sheet, said reinforcing sheet being equal in length to the inner and outer tubes and extending throughout the gusseted area of the bag and extending in from the gusseted area toward the opposite edge of the bag a fractional amount of the bag width thereby providing suflicient strength to replace the loss of strength caused by the cut-out area.

2. A valve bag comprising a body portion formed of outer, intermediate and inner members, said members being held together at one end and being infolded at one edge of the bag adjacent said end where they are held together to form a flap valve, the infolded portion of the intermediate member extending inwardly beyond the infolded portions of the outer and inner members at each side to form flap extensions adapted to be pressed together in sealing relationship, said intermediate memher having at each side thereof a cut-out space at the same edge of the bag as said infolded portions but at References Cited in the file of this patent the opposite end of the bag, and a reinforcing sheet be- UNITED STATES PATENTS tween said intermediate member and one of said other members, said reinforcing member extending the full 2339968 Frixione 1944 length of the bag, around said edge of the bag and to- 5 FOREIGN PATENTS wards the opposite edge of the bag a fractional amount of the bag width and completely over the cut-out space 22108 Austraha-"T 1930 683,467 Great Britain Nov. 26, 1952 in the said intermediate member, thereby providing sufficient strength to replace the loss of strength caused by the cut-out space. 10 

